Only owners of a class can delete it. Note that deleting a class permanently removes access to your class, assignments, channels, and calendar for everyone including yourself.
If you’d prefer to archive your class, follow these steps instead.
Navigate to the class you’d like to delete, then select the ellipses icon next to the class name.
Select Delete the team.
If you’re sure you want to delete the class, check the box and select Delete team.
Tip: If you’d like to recover an O365 group associated with your team, team owners and IT admins can recover deleted teams for up to 30 days. For more information, visit https://aka.ms/groupssoftdelete.